Raid devices fail to unmount during shutdown
When I shutdown or reboot my server, two of the four raid devices fail to unmount during shutdown but a few seconds after that the system normally goes offline. Namely, I have 4 raid partitions, md0-/boot md1-swap md2-/root and md3-/home. When I shutdown md2 and md3 fail to unmount properly (i get a green ok when unmounting the first two and a red fail after unmounting the last two).
Is this a serious error or should raid behave like that, as the two partitions are in use until the system shuts down.